Patent GB-248038-A (GB)
Title: Improvements in or relating to pumps
IPC: F04B7/00
Filed: 1924-11-20
Abstract: 248,038. Lunge, E., and Courtaulds, Ltd. Nov. 20, 1924. Cam-actuated pumps; multiple-delivery piston pumps; pumps for viscous liquids; valves, arrangement of; regulating delivery by by-passes or return conduits; pipes: mountings.- In a pumping-apparatus applicable for supplying viscose at a uniform rate to a spinning nozzle in the manufacture of artificial silk, one or more pumps having a cyclically fluctuating rate of delivery are used in conjunction with a cam-actuated additional pump, the actuating-cam of which is so determined that the additional pump counteracts the variations in the rate of delivery of the other pump or pumps. The apparatus may comprise two pumps actuated by similar cams and each having a rate of delivery varying according to a curve 59, Fig. 2, symmetrical about a centre line 60, the maximum delivery of one pump taking place during the suction period of the other pump, and vice versa. As shown in Figs. 5 and 6, the pump body 61 is bored longitudinally to form pump cylinders 73, 74 containing plungers 75, 76 operated by push rods 77, 78, and a valve chamber 62 for a reciprocating slide valve 80, rotation of which is prevented by a slot 83 in the valve stem 82 engaged by a, pin in the casing. A transverse bore 79 connects the valve chamber 62 with the pump cylinders 73, 74. Transverse bores 63, 64 serve as supply and return passages, and an outlet passage 68 is connected to a spinning nozzle. A transverse slide valve 67 can be adjusted to place the outlet port 66 of the valve chamber 62 in communication either with the outlet 66 or the return passage 64, the adjustment of the valve 67 not affecting the volume of the pump chambers. The valve 80 has separate recesses 84, 85 which place the supply passage 65 alternately in communication with one side or the other of the bore 79, leading to one or other pump cylinder, and overlapping recesses 86, 87 which put the pump cylinder in communication with the outlet port 66. A number of pump bodies 61 may be arranged end to end, as described in Specification 248,041, the plungers and valves abutting against those of adjacent units and being actuated by cams at the end of the assemblage, any of the plungers or valves being adjustable in length by means of a screw stud such as 81. The supply and return conduits 63, 64 in the units are in alignment and the fluid circulated through them by a rotary screw as described in Specification 248,046. The valves 67 enable individual pumps to be put out of action, without affecting the rest, by connecting the outlet port 69 to the return conduit 64. The pumps are secured to a channel-section rail 103, Fig. 10, fixed to a bench, by bolts 105 passing through lugs on the pump bodies 104 and through the sides of the rail and locating plates 106, the holes in the rail being large enough to allow the units to be accurately aligned. In a modification, the pump cylinders are arranged transversely to the valve-chamber, the pistons being operated by the means described in Specification 248,042. In a further form, both the valves and the pump cylinders are arranged transversely of the pump body, the valves being actuated by a reciprocating frame having lugs carrying pins engaging the valve stems.